Piston



May 20, 1941. COLE 2,242,345

PISTON Filed July 9, 1938 Z 2 I z j a W/////// 4 a v Patented May 20, 1941 UNITED STATES PATENT OFFICE PISTON Geor R. Cole, Fresno, Calif.

Application July 9, 1938, Serial No. 218,433

1 Claim.

This invention relates to an improved piston of the type used in internal combustion engines, and it is one object of the invention to provide a piston and method of making the same wherein the piston has a body formed of aluminum and a steel skirt which is applied to the body in an improved manner and cooperates with the body to form a piston havin a skirt of. a conventional depth.

Another object of the invention is to provide a piston consisting of an aluminum alloy body and a steel skirt and combining the advantages of aluminum alloy for heat dissipation with the wearing qualities of a steel skirt.

Another object of the invention is to so form the aluminum body and the steel skirt that the steel skirt which consists of companion sections may be disposed about the aluminum body and the sections of the skirt then firmly welded to each other.

It is another object of the invention to so form the body or head of the piston that in case the head should become broken the skirt will remain in engagement with arms terminat- Ing in bearings in which the connecting rod is mounted and thus permit the skirt to serve as a guide and prevent the piston rod and connecting rod from being thrown against walls of a cylinder and scarring the same or entirely wrecking the engine.

The invention is illustrated in the accompanying drawing, wherein Figure 1 is a sectional view taken longitudinally I through a piston of the improved construction,

Figure 2 is a longitudinal sectional view taken through the piston along the line 2-2 of Figure Figure 3 is a sectional view taken transversely through the piston along the line 33 of Figure 1, and

Figure 41s a perspective view of a fragment of the steel Jacket.

This improved piston has a body I formed of an aluminum alloy and consisting of a head 2 and a short skirt portion 3, the skirt portion being formed with the usual oircumierentially extending grooves 4 for receiving the piston rings. Arms 5 which are of short length extend downwardly from the skirt portion of the body at diametrically opposed portions thereof and terminate in bearing sleeves 6 which project inwardly, as shown in Figure 1, and are intended to receive the wrist pin of the usual piston rod. Reinforcing ribs I extend across the under face of the head 2 and at their ends are extended downwardly. as shown at 8, to provide reinforcements for marginal portions of the arms 5. The body I together with the arms 5 and the reinforcing ribs consist of a single casting.

The skirt 9 of this piston is formed of sheet steel or equivalent sheet material and consists of companion sections III which cooperate with each other to form a tubular skirt and have their side edges disposed in abutting engagement with each other, as shown in Figure 3, and secured by welded joints II. Opposed openings are formed in the section III and these openings are surrounded by inwardly extending sleeves which fit snugly about the outwardly projecting end portions of the sleeves or bosses 6. In view of the fact that the sleeves I2 fit about the outer end portions of the sleeves or bosses 6, the skirt will be held against movement circumferentially of the piston and also held against longitudinal movement. Therefore, the skirt will be maintained in its proper position and the inwardly extending flanges I3 at the upper ends of the sections III will be maintained in fiat contacting engagement with the lower edge face of the skirt portion of the body I. This will provide a wide annular bearing surface between the body I and the skirt 9. Referring to Figures 3 and 4, it will be seen that end portions of the flanges I3 are cut to form tongues I4 which extend circumferentially of the skirt and have their free end portions bent downwardly to Iorm lips I5 which bear against outer side faces of the ribs 8 at opposite sides of the arm 5. In view of the fact that the skirt consists of companion sheet metal sections, it may be easily assembled about the head and when the outer end portions of the sleeves or bearings 6 are engaged through the sleeves I2 the welded joint II may be formed along the abutting side edges of the sections Ill. The skirt 9 is located entirely below the skirt portion of the head and is held against movement circumferentially thereof not only by sleeves I2 which engage about the bearings 6 but also by the tongues I4 which have abutting engagement with opposite sides of the arms 5. In case the arms should be broken from the skirt portion of the body, the bearings 6 will remain within the sleeves I2 and the sheet metal skirt will then constitute means for guiding reciprocating movement or the piston rod which has its wrist pin engaged in the bearings. It will thus be seen that the piston rod and the wrist pin will be prevented from having undue movement transversely oi the cylinder in which the piston operates and scoring 01' the walls of the cylinder and -alloy and downwardly along the arms at opposite side edges thereof, a sheet metal skirt consisting .0! sections welded to each other and provided with sleeves engaged about outer end portions of the bearing sleeves of said arms, and an annular flange about the upper end of said skirt bearing against said head and having portions formed with circumferentially extending .tongues disposed at opposite sides 0! said arms and forming with lips at their ireeend abutting opposite side edge faces 01' the arms.

GEORGE R. COLE. 

